At present, the LED lights are prominently used as illumination sources. The dimmable LED lamps have been increasingly used, and in some specific fields, the LED lamps with higher power are required. Some of these fields require the LED lamps to have a power of 200 W, 300 W, or even higher. Moreover, some American standards aiming at the LED lamps require that the output current of the LED driver must not exceed 5 A and the output power must not exceed 100 W. For example, the standards UL1310 and UL8750 require that the nominal output current of the LED driver must not exceed 5 A and nominal output power must not exceed 100 W. Therefore, the existing LED drivers which can reach the power of 200 W, 300 W, or even higher do not meet the CLASS-2 standard.